Packaging method of infrared photodetector array and infrared photodetector

Abstract

This application provides a packaging method for an infrared photodetector array and an infrared photodetector, relating to the field of detector packaging technology. The packaging method first fabricates multiple second substrates on a first substrate, the multiple second substrates having a patterned structure; then, a periodic array of superlens units is fabricated on the second substrates; a thin-film getter is sputtered around the superlens; a first bonding ring is connected around the thin-film getter using a sputtering process, and a second bonding ring is connected around the detector wafer; the first and second bonding rings are connected to achieve a vacuum-sealed state between the superlens and the detector wafer; finally, the thin-film getter is activated to maintain the vacuum-sealed state. In the above method, a material with high transmittance in the infrared band is used as the superlens substrate and the periodic array of superlens units, improving the light transmittance of the infrared photodetector, and the patterned structure of the second substrate improves the production efficiency of the infrared photodetector.

Description

Technical Field

[0001] This application relates to the field of detector packaging technology, and in particular to a packaging method for an infrared photodetector array and an infrared photodetector. Background Technology

[0002] In the field of optoelectronic technology, the performance of optoelectronic core devices continues to be optimized with the improvement of materials and processes. Because of their small size, further optimization of optoelectronic devices can be achieved through improvements in packaging methods, thereby enhancing their performance and stability. Specifically, packaging technology for uncooled infrared detector arrays is developing towards miniaturization and integration to meet the demands of low cost, high heat dissipation, and large-scale production.

[0003] Currently, wafer-level packaging is a commonly used packaging technology for uncooled infrared detector arrays, offering advantages such as small size, low cost, and suitability for mass production. Traditional wafer-level packaging structures use a flat lens with convex lens function to achieve focusing, and deposit an anti-reflective film on the surface of the convex lens to improve light transmittance; at the same time, the packaging process involves the processing and bonding of the cover wafer, forming a single detector through steps such as dicing.

[0004] However, infrared photodetectors manufactured using traditional wafer-level packaging have high light reflectivity, which easily generates interference noise and affects the photoelectric performance of the detector. Although the convex and flat lenses used in this technology are treated with anti-reflection coatings, they still have high reflection efficiency and can only achieve light focusing at small angles, which cannot meet the high-precision detection requirements in complex environments. In addition, in traditional packaging processes, the cover wafer needs to be cut into individual chip caps, which is not conducive to mass production and reduces the production efficiency of infrared photodetectors. Summary of the Invention

[0005] To address the aforementioned issues, this application provides a packaging method for an infrared photodetector array and an infrared photodetector. This method can solve the technical problems of high light reflectivity and interference noise in the packaged infrared photodetector, which leads to reduced performance, as well as the complex packaging process, which results in low production efficiency.

[0006] To achieve the above objectives, the first aspect of this application provides a packaging method for an infrared photodetector array. The method involves fabricating multiple second substrates on a first substrate using photolithography. The first substrate and the multiple second substrates are made of materials with high transmittance in the infrared band, and the multiple second substrates have a patterned structure. A superlens unit array is fabricated on the second substrates using photolithography and dry etching processes. The superlens unit array has a periodic structure. A thin-film getter is sputtered around the superlens. The superlens includes a first substrate, a second substrate, and the superlens unit array located on the second substrates. A detector wafer is provided, comprising multiple independent infrared photodetector units arranged in an array. A first bonding ring is connected around the thin-film getter using a sputtering process, and a second bonding ring is connected around the detector wafer. The first and second bonding rings are connected to achieve a vacuum-sealed state between the superlens and the detector wafer. The thin-film getter is activated to maintain the vacuum-sealed state.

[0007] In the aforementioned packaging method, using a material with high transmittance in the infrared band as the superlens substrate can improve the light transmittance of the packaged infrared photodetector. Simultaneously, the second substrate has a patterned structure, which can match the shape of the detector wafer, reducing the complexity of the cutting process and improving the production efficiency of the infrared photodetector. Furthermore, designing a periodic superlens unit array can improve the transmittance of the infrared photodetector over a wide angle range in the mid-infrared band, further enhancing the light transmittance of the packaged infrared photodetector.

[0008] In one possible implementation of the first aspect, the shape of each second substrate matches the package shape of the infrared photodetector unit.

[0009] In the above packaging method, the shape of the second substrate matches the packaging shape of the infrared photoelectric detection unit, which can make the cover wafer and the detector wafer tightly bonded, thereby improving the accuracy of the packaged infrared photoelectric detector.

[0010] In one possible implementation of the first aspect, the superlens unit array includes multiple superlens units arranged periodically on a second substrate, with an arrangement period less than or equal to 1 μm; the arrangement period is equal to the length of the bottom diameter of the superlens unit.

[0011] In the above packaging method, the light transmittance of the superlens is improved by designing a suitable arrangement period, the influence of interference effect is reduced, and the performance of the infrared photodetector is improved.

[0012] In one possible implementation of the first aspect, each superlens unit in the superlens unit array is identical, and the superlens units have a symmetrical structure.

[0013] In the above packaging method, the superlens unit array uses identical and symmetrical superlens units, which can improve the light transmittance of the superlens, reduce the influence of interference effects, and improve the performance of the infrared photodetector.

[0014] In one possible implementation of the first aspect, the superlens unit is a metasurface structure with a 2π phase change.

[0015] In the above packaging method, the superlens unit adopts a 2π phase metasurface structure, which can disrupt the coherent reflection optical path and improve the light transmittance of the infrared photodetector.

[0016] In one possible implementation of the first aspect, the thin-film getter is a low-temperature getter with an activation temperature below 300°C; the thin-film getter is an alloy material, and the width of the thin-film getter is greater than 300 μm and less than 600 μm.

[0017] In the above encapsulation methods, selecting an appropriate thin-film getter width and an appropriate activation temperature can improve the precision of infrared photodetector encapsulation.

[0018] In one possible implementation of the first aspect, the first bonding ring and the second bonding ring are of the same size; the widths of the first bonding ring and the second bonding ring are greater than 400 μm and less than 600 μm.

[0019] In the above packaging method, the cover wafer and the detector wafer are sealed with first and second bonding rings of the same size, which can improve the tightness of the seal. Setting an appropriate width for the bonding ring can improve the reliability of the packaging.

[0020] In one possible implementation of the first aspect, a plurality of second substrates are fabricated on a first substrate using a chemical deposition process, wherein the first and second substrates are made of the same material; or, a plurality of second substrates are fabricated on a first substrate using a dry etching process.

[0021] In the above-described packaging method, multiple second substrates can be fabricated on the first substrate using either chemical deposition or dry etching, thus enhancing the diversity of the packaging method. Furthermore, when using chemical deposition, it is necessary to ensure that the first and second substrates are made of the same material with high transmittance in the infrared band, which can improve the uniformity and light transmittance of the infrared photodetector. Similarly, the second substrates fabricated using dry etching must be made of the same material as the first substrate, which also improves the uniformity and light transmittance of the infrared photodetector.

[0022] In one possible implementation of the first aspect, the height of the superlens is greater than 40% of the peak operating wavelength of the infrared photoelectric detection unit and less than the peak operating wavelength of the infrared photoelectric detection unit.

[0023] In the above packaging method, selecting a superlens with a height between 40% and 100% of the operating peak wavelength of the infrared photodetector unit to package the detector wafer can improve the light transmittance of the packaged infrared photodetector.

[0024] Secondly, this application also provides an infrared photodetector, which is fabricated based on the packaging method of the infrared photodetector array in the first aspect and any possible implementation thereof. The infrared photodetector includes: a cover wafer, the cover wafer including: a superlens, and a thin film getter disposed around the superlens; wherein, the superlens includes a first substrate, a plurality of patterned second substrates located on the first substrate, and a superlens unit array located on the second substrate; a detector wafer including: a substrate and a plurality of independent infrared photodetector units arranged in an array on the substrate; the substrate includes a GaSb substrate layer, a P-type layer, a light-emitting layer, an n-type layer, and electrodes; the shape of each second substrate matches the packaging shape of the infrared photodetector unit; a first bonding ring connecting the periphery of the thin film getter, and a second bonding ring connecting the periphery of the detector wafer; wherein, the first bonding ring and the second bonding ring are connected to form a vacuum-sealed structure between the cover wafer and the detector wafer.

[0025] It is understood that the beneficial effects of the technical solution of the second aspect provided above can be referred to the beneficial effects of the first aspect and any of its optional implementation methods, and will not be repeated here.

[0026] As can be seen from the above technical solutions, this application provides a packaging method for an infrared photodetector array and an infrared photodetector. The packaging method for the infrared photodetector array employs photolithography to fabricate multiple second substrates on a first substrate. The first substrate and the multiple second substrates are made of materials with high transmittance in the infrared band, and the multiple second substrates have a patterned structure. A superlens unit array is fabricated on the second substrate using photolithography and dry etching processes. The superlens unit array has a periodic structure. A thin-film getter is sputtered around the superlens. The superlens includes a first substrate, a second substrate, and the superlens unit array located on the second substrate. A detector wafer is provided, comprising multiple independent infrared photodetector units arranged in an array. A first bonding ring is connected around the thin-film getter using a sputtering process, and a second bonding ring is connected around the detector wafer. The first and second bonding rings are connected to achieve a vacuum-sealed state between the superlens and the detector wafer. The thin-film getter is activated to maintain the vacuum-sealed state.

[0027] In the aforementioned packaging method, using a material with high transmittance in the infrared band as the superlens substrate can improve the light transmittance of the packaged infrared photodetector. Simultaneously, the second substrate has a patterned structure, which can match the shape of the detector wafer, reducing the complexity of the cutting process and improving the production efficiency of the infrared photodetector. Furthermore, designing a periodic superlens unit array can improve the transmittance of the infrared photodetector over a wide angle range in the mid-infrared band, further enhancing the light transmittance of the packaged infrared photodetector. Attached Figure Description

[0028] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 A schematic diagram of a packaging method for an infrared photodetector array provided in an embodiment of this application;

[0030] Figure 2 A top view of a superlens structure provided in an embodiment of this application;

[0031] Figure 3 A top view of a detector wafer structure provided in an embodiment of this application;

[0032] Figure 4 This is a schematic cross-sectional view of a superlens structure provided in an embodiment of this application;

[0033] Figure 5 This is a schematic diagram of a cover plate wafer structure provided in an embodiment of this application;

[0034] Figure 6 This is a schematic diagram of a bonding structure provided in an embodiment of this application.

[0035] Figure label:

[0036] 1-Superlens unit; 2-Second substrate; 201-Superlens unit array; 3-First substrate; 4-Superlens; 5-Thin film getter; 601-First bonding ring; 602-Second bonding ring; 7-Infrared photoelectric detection unit; 8-Substrate; 9-Detector wafer; 10-Cover wafer. Detailed Implementation

[0037] The embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following examples do not represent all embodiments consistent with this application.

[0038] It should be noted that the brief descriptions of terms in this application are only for the convenience of understanding the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise stated, these terms should be understood in their ordinary and common meaning.

[0039] The terms "first," "second," "third," etc., used in the specification and accompanying drawings of this application are used to distinguish similar or related objects or entities, and do not necessarily imply a specific order or sequence, unless otherwise specified. It should be understood that such terms can be used interchangeably where appropriate.

[0040] To facilitate understanding of the plan, the following explanations are provided for relevant terms:

[0041] Superlens: A planar optical element based on a metasurface. Its core principle is to use subwavelength-scale artificial nanostructure units to precisely control the phase, amplitude, or polarization state of incident light, thereby achieving the functions of a traditional lens, such as focusing and imaging.

[0042] Detector wafer: refers to a semiconductor wafer specifically designed and manufactured for detecting light, particles, or other forms of energy. Its core function is to convert incident energy (such as photons, electrons, X-rays, alpha particles, etc.) into measurable electrical signals.

[0043] Cover wafer: In semiconductor manufacturing, this refers to a special wafer used to seal and protect the underlying device wafer (such as a detector wafer). Its core function is to provide a physical barrier, isolating sensitive devices from the external environment.

[0044] Thin-film getters: refer to ultra-thin active material layers deposited on the surface of devices (such as vacuum or hermetically sealed cavities). Their core function is to actively adsorb or chemically capture harmful gas molecules and contaminants that remain or are slowly released inside the package, thereby maintaining the required high vacuum or pure inert gas environment for a long time.

[0045] Bonding ring: refers to the ring-shaped sealing structure designed on the surface of a wafer in semiconductor manufacturing. Its core function is to achieve precise alignment, firm bonding and hermetic sealing between two wafers (such as a detector wafer and a cover wafer).

[0046] In the field of infrared photodetector fabrication, packaging is necessary to improve the performance, operational stability, and lifespan of infrared photodetectors. Wafer-level packaging is a commonly used packaging technology, offering advantages such as small size and low cost.

[0047] Traditional wafer-level packaging structures use a flat lens with convex lens function to achieve focusing, and deposit an anti-reflective film on the surface of the convex lens to improve light transmittance; at the same time, the packaging process involves the processing and bonding of cover wafers, forming a single detector through steps such as dicing.

[0048] Wafer-level packaging technology uses a flat lens with convex lens function to achieve focusing. An anti-reflective coating is deposited on the surface of the convex lens to improve light transmittance. However, the light reflection efficiency is still relatively high, and it can only achieve a small-angle focusing effect, which cannot meet the high-precision detection requirements in complex environments. Moreover, the reflected light will generate interference noise, reducing the detector's operating performance. In addition, in traditional packaging processes, the cover wafer needs to be diced into individual chip caps, which is not conducive to mass production and reduces the production efficiency of infrared photodetectors.

[0049] To address the aforementioned technical problems, this application provides a packaging method for an infrared photodetector array, which can improve the light transmittance of the packaged infrared photodetector, reduce the reflection loss of infrared light at large angles and the influence of interference effects, thereby improving the performance of the infrared photodetector.

[0050] The packaging method for the infrared photodetector array provided in this application uses a superlens structure to fabricate a cover wafer 10, and then seals the cover wafer 10 and the detector wafer 9 with two bonding rings.

[0051] Figure 1 This is a schematic diagram illustrating a packaging method for an infrared photodetector array provided in an embodiment of this application. Figure 1 As shown, the packaging method for the infrared photodetector array includes steps S1-S7.

[0052] Step S1: Provide the first substrate 3.

[0053] Figure 2 This is a top view of a superlens structure provided in an embodiment of this application. Figure 2 As shown, the bottom layer of the superlens structure is the first substrate 3.

[0054] In some embodiments, the first substrate 3 is a material with high transmittance in the infrared band. For example, materials with high transmittance in the infrared band, such as silicon, germanium, and zinc sulfide, are used as the first substrate 3.

[0055] Step S2: Create multiple second substrates 2.

[0056] For example Figure 2 As shown, there are multiple second substrates 2 on the upper layer of the first substrate 3.

[0057] In some embodiments, a plurality of second substrates 2 are fabricated on a first substrate 3 using a photolithography process. The plurality of second substrates 2 are made of materials with high transmittance in the infrared band. For example, materials with high transmittance in the infrared band, such as silicon, germanium, and zinc sulfide, are used as the second substrates 2.

[0058] In some embodiments, to enhance the diversity of packaging methods, multiple second substrates 2 can be fabricated on the first substrate 3 using two processes, such as chemical deposition or dry etching.

[0059] In some embodiments, to improve the uniformity of the superlens structure, the first substrate 3 and the second substrate 2 are made of the same material.

[0060] For example, if a plurality of second substrates 2 are fabricated on a first substrate 3 using a chemical deposition process, then both the first substrate 3 and the second substrate 2 are made of silicon.

[0061] For another example, if a dry etching process is used to fabricate multiple second substrates 2 on a first substrate 3, and the first substrate 3 is made of silicon, then since the dry etching process involves etching directly on the first substrate 3, the material of the etched second substrate 2 must be the same as that of the first substrate 3, and the material of the second substrate 2 is also silicon.

[0062] Figure 3 This is a top view of a detector wafer structure provided in an embodiment of this application. Figure 3 As shown, the detector wafer 9 includes a substrate 8 and multiple independent infrared photoelectric detection units 7 arranged in an array on the substrate 8.

[0063] In some embodiments, in order to reduce the process complexity of the infrared photodetector during the packaging process, avoid cutting the cover wafer 10 into individual caps before packaging, and improve the efficiency of large-scale packaging of the infrared photodetector, each second substrate 2 can be fabricated as a patterned structure that matches the shape of the infrared photodetector unit 7 in the detector wafer 9.

[0064] For example, if the infrared photodetector unit 7 in the detector wafer 9 is square, then each second substrate 2 is also fabricated as a square structure. Thus, the packaged infrared photodetector array comprises multiple square-structured infrared photodetectors. The infrared photodetector array can then be diced into individual infrared photodetectors using a dicing process, improving the efficiency of large-scale production of infrared photodetectors.

[0065] It should be understood that the shape of the second substrate 2 can be adjusted according to the packaging requirements of the detector wafer 9, and no specific limitation is made in the embodiments of this application.

[0066] S3: Fabricate the superlens unit array 201.

[0067] For example Figure 2 As shown, each second substrate 2 includes a set of superlens unit arrays 201. In some embodiments, the superlens unit arrays 201 are fabricated on the second substrate 2 using photolithography and dry etching processes.

[0068] In one implementation, a superlens structure is used to package the detector wafer 9. To improve the light transmittance of the packaged infrared photodetector over a wide angular range in the mid-infrared band, the superlens unit array 201 can be configured as a periodic structure composed of multiple superlens units 1, with each superlens unit 1 in the superlens unit array 201 arranged periodically on the second substrate 2. For example, the arrangement period of the superlens units 1 is less than or equal to 1 μm.

[0069] In some embodiments, to further improve the light transmittance of the packaged infrared photodetector over a wide angular range in the mid-infrared band, each superlens unit 1 in the superlens unit array 201 is configured to have the same structure and be symmetrical.

[0070] Figure 4 This is a schematic cross-sectional view of a superlens structure provided in an embodiment of this application.

[0071] like Figure 4 As shown, each superlens unit 1 in the superlens unit array 201 is a waisted structure with the same structure.

[0072] It should be understood that the superlens unit 1 can also be other symmetrical structures, such as cylindrical, frustum-shaped, etc., and no specific limitation is made in the embodiments of this application.

[0073] Furthermore, to improve the light transmittance of the packaged infrared photodetector over a wide angular range in the mid-infrared band, the arrangement period of the superlens unit 1 is set to be equal to the length of the bottom diameter of the superlens unit 1. For example, the bottom diameter of the superlens unit 1 is 1 μm, and the arrangement period of the superlens unit 1 is also 1 μm.

[0074] In other embodiments, to improve light transmittance, a suitable size can be selected for the superlens unit 1. For example, if the superlens unit 1 is a waisted structure, the waist height of the superlens unit 1 is set to 20%-30% of the height of the superlens unit 1.

[0075] In some other embodiments, the height of the superlens 4 can be set according to the operating peak wavelength of the infrared photodetector unit 7 on the detector wafer 9. For example, the height of the superlens 4 is greater than 40% of the operating peak wavelength of the infrared photodetector unit 7 and less than the operating peak wavelength of the infrared photodetector unit 7.

[0076] In this way, by fabricating multiple identical superlens units 1 with specific structures (such as a waisted symmetrical structure, with a waist height of 20% of the overall height and a height of 40% of the working peak wavelength of the infrared photodetector 7) on the second substrate 2, and setting the arrangement period of the superlens units 1 to be the same as the bottom diameter of the superlens units 1, the encapsulated infrared photodetector can achieve a large angular range of transmittance greater than 99% in the mid-infrared band, thereby improving the performance of the infrared photodetector.

[0077] In some embodiments, the superlens unit 1 is a metasurface structure with a 2π phase change. This allows the perpendicularly incident light to be focused onto the photosensitive surface of the detector wafer 9, further improving the transmittance of the infrared photodetector to the incident light.

[0078] S4: Sputtered film getter 5.

[0079] Figure 5 This is a schematic diagram of a cover plate wafer structure provided in an embodiment of this application.

[0080] like Figure 5 As shown, the cover wafer 10 used to encapsulate the detector wafer 9 includes a superlens 4 composed of a first substrate 3, a second substrate 2 and a superlens unit array 201 located on the second substrate 2, a thin film getter 5 and a first bonding ring 601.

[0081] In some embodiments, to achieve a seal between the cover wafer 10 and the detector wafer 9, a thin film getter 5 is first sputtered around the superlens 4.

[0082] In one implementation, to avoid damage to the detector wafer 9 caused by high temperatures, the thin-film getter 5 is a low-temperature getter with an activation temperature below 300°C. For example, a thin-film getter 5 with an activation temperature of 200°C is sputtered around the superlens 4.

[0083] In another implementation, to improve the stability of the packaged device, the thin-film getter 5 can be made of an alloy material, and its width is set between 300 μm and 600 μm. For example, Ti-V or Ti-Zr-V can be selected as the thin-film getter 5, and the width of the thin-film getter 5 sputtered around the superlens 4 is 400 μm.

[0084] Step S5: Provide detector wafer 9.

[0085] In some embodiments, once the cover wafer 10 is fabricated, the detector wafer 9 can be provided, and the sealing operation between the cover wafer 10 and the detector wafer 9 can continue.

[0086] Step S6: Connect the bonding ring.

[0087] In some embodiments, once the cover wafer 10 and the detector wafer 9 are both prepared, they need to be sealed to achieve the encapsulation of the infrared photodetector array.

[0088] In one implementation, to avoid dicing the cover wafer 10 into individual caps before sealing, a chip-to-wafer bonding process can be used. Since chip-to-wafer bonding allows for the integration of different process nodes on the same wafer, it overcomes the manufacturing limitations of a single wafer. Therefore, by using chip-to-wafer bonding, the cover wafer 10, which includes multiple superlens unit arrays 201, and the detector wafer 9, which includes multiple infrared photodetector units 7, can be bonded, improving the efficiency of large-scale production.

[0089] Figure 6 This is a schematic diagram of a bonding structure provided in an embodiment of this application.

[0090] In one implementation, firstly, a first bonding ring 601 is attached to the periphery of the thin film getter 5 by sputtering, and a second bonding ring 602 is attached to the periphery of the detector wafer 9.

[0091] In some embodiments, to improve the stability of the encapsulation structure, a first bonding ring 601 and a second bonding ring 602 of the same size are connected around the periphery of the thin-film getter 5 and around the periphery of the detector wafer 9, and the widths of the first bonding ring 601 and the second bonding ring 602 are set to 400μm-600μm. For example, a first bonding ring 601 with a width of 500μm and a second bonding ring 602 with a width of 500μm are connected around the periphery of the thin-film getter 5 and around the periphery of the detector wafer 9, respectively.

[0092] Next, the first bonding ring 601 and the second bonding ring 602 are connected to create a vacuum-sealed state between the superlens 4 and the detector wafer 9. For example, as shown... Figure 6 As shown, the first bonding ring 601 and the second bonding ring 602 are tightly connected to achieve the effect of sealing the superlens 4 and the detector wafer 9.

[0093] Finally, the membrane getter 5 is activated to maintain a vacuum seal.

[0094] Based on the above steps S1-S6, the packaging of the detector wafer 9 with a superlens 4 of a specific structure and periodic arrangement can be completed. Since the packaging process uses a superlens 4 with multiple superlens unit arrays 201 and a detector wafer 9 with multiple infrared photodetector units 7, the packaged infrared photodetector array can be cut by a dicing process to obtain a single infrared photodetector.

[0095] This application proposes a packaging method for an infrared photodetector array. A cover wafer 10 is fabricated using superlens units 1 with a specific structure and periodically arranged in a certain proportion to package the detector wafer 9. It should be understood that this cover wafer 10 can also be used to package other mid-wave and short-wave uncooled infrared detectors; however, this application does not impose specific limitations on this method.

[0096] This application embodiment also provides an infrared photodetector, which is fabricated based on the packaging method of the infrared photodetector array in the above embodiment. The infrared photodetector includes: a cover wafer 10, the cover wafer 10 including: a superlens 4, and a thin film getter 5 disposed around the superlens 4; wherein, the superlens 4 includes a first substrate 3, a plurality of patterned second substrates 2 located on the first substrate 3, and a superlens unit array 201 located on the second substrate 2; a detector wafer 9 including: a substrate 8 and a plurality of independent infrared photodetector units 7 arranged in an array on the substrate 8; the substrate 8 includes a GaSb substrate layer, a p-type layer, a light-emitting layer, an n-type layer, and electrodes; the shape of each second substrate 2 matches the packaging shape of the infrared photodetector unit 7; a first bonding ring 601 connecting the periphery of the thin film getter 5, and a second bonding ring 602 connecting the periphery of the detector wafer 9; wherein, the first bonding ring 601 and the second bonding ring 602 are connected to form a vacuum-sealed structure between the cover wafer 10 and the detector wafer 9.

[0097] As can be seen from the above technical solutions, this application provides a packaging method for an infrared photodetector array and an infrared photodetector. The packaging method for the infrared photodetector array employs photolithography to fabricate multiple second substrates 2 on a first substrate 3. The first substrate 3 and the multiple second substrates 2 are made of materials with high transmittance in the infrared band, and the multiple second substrates 2 are patterned structures. A superlens unit array 201 is fabricated on the second substrates 2 using photolithography and dry etching processes. The superlens unit array 201 has a periodic structure. A thin-film getter 5 is sputtered around a superlens 4. The superlens 4 includes the first substrate 3, the second substrates 2, and the superlens unit array 201 located on the second substrates 2. A detector wafer 9 is provided, comprising multiple independent infrared photodetector units 7 arranged in an array. A first bonding ring 601 is connected around the thin-film getter 5 using a sputtering process, and a second bonding ring 602 is connected around the detector wafer 9. The first bonding ring 601 and the second bonding ring 602 are connected to achieve a vacuum-sealed state between the superlens 4 and the detector wafer 9. The thin-film getter 5 is activated to maintain the vacuum-sealed state.

[0098] In the above packaging method, using a material with high transmittance in the infrared band as the superlens substrate can improve the light transmittance of the packaged infrared photodetector. Simultaneously, the second substrate 2 has a patterned structure that can match the shape of the detector wafer 9, reducing the complexity of the cutting process and improving the production efficiency of the infrared photodetector. Furthermore, designing a periodic superlens unit array 201 can improve the large-angle range of transmittance of the infrared photodetector in the mid-infrared band, further enhancing the light transmittance of the packaged infrared photodetector.

[0099] Similar parts between the embodiments provided in this application can be referred to mutually. The specific implementation methods provided above are only a few examples under the overall concept of this application and do not constitute a limitation on the scope of protection of this application. For those skilled in the art, any other implementation methods extended from the solution of this application without creative effort shall fall within the scope of protection of this application.

Claims

1. A packaging method for an infrared photodetector array, characterized in that, Multiple second substrates (2) are fabricated on a first substrate (3) using chemical deposition or dry etching processes. The first substrate (3) and the second substrates (2) are made of the same material. The first substrate (3) and the multiple second substrates (2) are made of materials with high transmittance in the infrared band, including silicon, germanium, or zinc sulfide. The multiple second substrates (2) are patterned structures. A superlens unit array (201) is fabricated on the second substrate (2) using photolithography and dry etching processes. The superlens unit array (201) is a periodic structure. A thin film getter (5) is sputtered around the superlens (4). The superlens (4) includes the first substrate (3), the second substrate (2), and the superlens unit array (201) located on the second substrate (2). A detector wafer (9) is provided, the detector wafer (9) comprising a plurality of independent infrared photodetector units (7) arranged in an array; wherein the shape of each of the second substrates (2) matches the package shape of the infrared photodetector unit (7); A first bonding ring (601) is attached to the periphery of the thin film getter (5) by sputtering process, and a second bonding ring (602) is attached to the periphery of the detector wafer (9). The first bonding ring (601) and the second bonding ring (602) are connected to make the superlens (4) and the detector wafer (9) vacuum sealed; The getter film (5) is activated to maintain the vacuum seal.

2. The packaging method for an infrared photodetector array according to claim 1, characterized in that, The superlens unit array (201) includes multiple superlens units (1), which are periodically arranged on the second substrate (2) with an arrangement period of less than or equal to 1 μm; The arrangement period is equal to the length of the bottom diameter of the superlens unit (1).

3. The packaging method for the infrared photodetector array according to claim 2, characterized in that, Each of the superlens units (1) in the superlens unit array (201) is identical, and the superlens units (1) have a symmetrical structure.

4. The packaging method for the infrared photodetector array according to claim 3, characterized in that, The superlens unit (1) is a metasurface structure with a 2π phase change.

5. The packaging method for an infrared photodetector array according to claim 1, characterized in that, The film getter (5) is a low-temperature getter with an activation temperature below 300°C; The thin-film getter (5) is an alloy material, and the width of the thin-film getter (5) is greater than 300 μm and less than 600 μm.

6. The packaging method for an infrared photodetector array according to claim 5, characterized in that, The first bonding ring (601) and the second bonding ring (602) are the same size; The widths of the first bonding ring (601) and the second bonding ring (602) are greater than 400 μm and less than 600 μm.

7. The packaging method for an infrared photodetector array according to claim 1, characterized in that, The height of the superlens (4) is greater than 40% of the working peak wavelength of the infrared photoelectric detection unit (7) and less than the working peak wavelength of the infrared photoelectric detection unit (7).

8. An infrared photodetector, said infrared photodetector being manufactured based on the packaging method of an infrared photodetector array according to any one of claims 1-7, characterized in that, include: The cover plate wafer (10) includes: a superlens (4) and a thin film getter (5) disposed around the superlens (4); wherein the superlens (4) includes a first substrate (3), a plurality of patterned second substrates (2) located on the first substrate (3), and a superlens unit array (201) located on the second substrates (2). The detector wafer (9) includes: a substrate (8) and a plurality of independent infrared photodetector units (7) arranged in an array on the substrate (8); the substrate (8) includes a GaSb substrate layer, a P-type layer, a light-emitting layer, an n-type layer and electrodes; the shape of each second substrate (2) matches the package shape of the infrared photodetector unit (7); A first bonding ring (601) connecting the periphery of the thin film getter (5) and a second bonding ring (602) connecting the periphery of the detector wafer (9); The first bonding ring (601) is connected to the second bonding ring (602), so that the cover plate wafer (10) and the detector wafer (9) form a vacuum-sealed structure.

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